browser_open

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

With no annotations, the description carries the full burden and does so well: it discloses that reopening a live browser discards prior state ("what it held is gone"), that `support` is ephemeral and not saved, that the two identities share nothing, and how proxy defaults are inherited. It does not cover failure modes or permission requirements, so it stops short of a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loads the main/support distinction before the reopening caveat and the parameter glossary, and each sentence carries information. It is dense rather than padded, though the parameter list is slightly verbose given the tool's inherent complexity.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a 4-parameter tool with no annotations, no required params, and 0% schema coverage, the description covers all parameters, destruction/persistence behavior, and defaults. An output schema exists, so return values need not be explained here.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 0%, so the description must compensate and it does: seed (identity determinism, random when omitted), profile (persists cookies/logins/seed, "" means none), and proxy (full URI syntax, "" meaning, default inheritance from main) are all explained with semantics beyond the bare types.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a concrete verb (Open/reopen) and the two named resources (main, support), and defines what each identity is. It also names the sibling browser_close for the complementary action, so an agent can place it in the toolset without opening the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives explicit when-to-use guidance: open `support` when the task needs a second identity, and close it with browser_close as soon as the task no longer needs it, before answering. It names the alternative tool and the condition that selects it.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.